What four bike towball mounted rack?

Have got a Thule Ride On 3 bike carrier that we used on the Mondeo, which is fine, but that was with fourth bike in boot, which with light brown/cream interior on the Passat that has replaced it that isn't an option anymore (plus it was a pain).

So do I have to spend £500 on another Thule or are there any decent alternatives?

I bought A Halfords Advanced one two years ago for about £250-£300, very good and going strong. Folds up small enough to go in the boot whilst you are riding for the day, and doesn't take up too much room in the garage. Vertical dividers prevent bikes rubbing except some bikes that don't "tesselate" well - I just use some pipe lagging for protection there. Also you can tilt the whole thing backwards with 4 bikes on it to get access to the boot. Setting up and fitting to the car took me a pestering-child-free hour or so initially but thereafter it takes only 5-10minutes to get four bikes loaded up each time. Quick releases from the towbar in seconds.